50% stock margin after 3:50 EST at IB

Can someone tell me if I enter into a long stock position that exceeds the 50% margin requirement before 3:50pm, does Interactive Broker actually forcibly liquidate part of my position at the close?

For e.g. if I were day trading and bought $400,000 worth of stock with only $100,000 cash, and I forgot to sell the position before 3:50pm, would IB sell $200,000 worth of stocks for me at the market close?

I know people has asked about this before, but that was in 2003, so I don't know if the situation is the same now in Dec 2005.